regulator: s2mpa01: Drop useless header

The TPS65910 includes the legacy header <linux/gpio.h> for no
reason, drop the include.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230808-descriptors-regulator-v1-2-939b5e84dd18@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/s2mpa01.c

@@ -5,7 +5,6 @@
 
 #include <linux/bug.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/of.h>